uaac curl works but uaa curl does not.

Good day, I am trying to figure out the difference between the Ruby uaac and Go uaa when using curl to update OpsMan authentication settings.
Below env vars are used in both cases:

# Env Vars
ENV_NAME=sandbox
opsman_password=$(credhub get -n "/concourse/${ENV_NAME}/opsman_password" -q)
decryption_passphrase=$(credhub get -n "/concourse/${ENV_NAME}/opsman_decryption_passphrase" -q)
unlock_user_password=$(credhub get -n "/concourse/${ENV_NAME}/opsman_unlock_user_password" -q)
payload="{
  \"authentication\": {
    \"decryption_passphrase\": \"${decryption_passphrase}\",
    \"identity_provider\": \"internal\",
    \"admin_user_name\": \"admin\",
    \"admin_password\": \"${opsman_password}\",
    \"admin_password_confirmation\": \"${opsman_password}\"
  }
}"

This works (Ruby uaac):

uaac target https://pcf.${ENV_NAME}.westeurope.api.mtn.com/uaa
uaac token owner get opsman unlock_user -s '' -p "${unlock_user_password}"

uaac curl -X PUT -H "Content-type: application/json" https://pcf.${ENV_NAME}.westeurope.api.mtn.com/api/v0/settings/authentication -d "${payload}"

I get:

--snip--
200 OK
--snip--

and in the OpsMan access.log:

155.93.175.238 - opsman [20/Apr/2021:10:09:35 +0000] "POST /uaa/oauth/token HTTP/1.1" 200 2532 "-" "HTTPClient/1.0 (2.8.3, ruby 2.5.1 (2018-03-29))"
155.93.175.238 - - [20/Apr/2021:10:09:51 +0000] "PUT /api/v0/settings/authentication HTTP/1.1" 200 12 "-" "Ruby"

This does not work (Go uaac):

./uaa target https://pcf.${ENV_NAME}.westeurope.api.mtn.com/uaa
./uaa get-password-token opsman -s '' -u unlock_user -p "${unlock_user_password}"

./uaa curl -X PUT -H "Content-type: application/json" https://pcf.${ENV_NAME}.westeurope.api.mtn.com/api/v0/settings/authentication -d "${payload}"

I get:

--snip--
        <div class="alert alert-error">
            <p>Invalid login attempt, the request does not meet our security standards and may indicate that the action was not originated by you. Please try again.</p>
        </div>
--snip--

and in the OpsMan access.log:

155.93.175.238 - opsman [20/Apr/2021:09:55:09 +0000] "POST /uaa/oauth/token HTTP/1.1" 200 2516 "-" "Go-http-client/1.1"
155.93.175.238 - - [20/Apr/2021:09:57:41 +0000] "PUT /uaa/https:/pcf.sandbox.westeurope.api.mtn.com/api/v0/settings/authentication HTTP/1.1" 302 0 "-" "Go-http-client/1.1"
155.93.175.238 - - [20/Apr/2021:09:57:41 +0000] "GET /uaa/login?error=invalid_login_request HTTP/1.1" 200 49404 "https://pcf.sandbox.westeurope.api.mtn.com/uaa/https:/pcf.sandbox.westeurope.api.mtn.com/api/v0/settings/authentication" "Go-http-client/1.1"

Reproduce the shown Ruby and Go uaac/uaa curl commands and compare the access.log requests. Start at the uaa curl command entry point and trace how the target URL is combined with the requested URL. Done means the Go command sends the PUT to /api/v0/settings/authentication without the duplicated /uaa/https:/ prefix and receives the successful response.